This invention relates to a system for treating wastewater and more particularly for the treatment of wastewater including the use of filtering materials as aerobic biofilters in a biofilter treatment tank.
In the treatment of wastewater, such as sewage and the like, it is common to provide a septic tank with an inlet in an upper portion to receive the wastewater. The septic tank is provided with, and generally on the opposite side from the inlet, an outlet discharge which is in flow communication with laterals for discharging effluent into an open field or the like. In the septic tank, the particulate materials settle to the bottom and it is the effluent which is removed through the laterals. Moreover, it has become common practice to install filters at the outlet discharge from the septic tank to remove undissolved solid particulate materials thereby preventing said materials from entering into the lateral field.
In recent years, it has been suggested to even further treat effluent from a septic tank before the wastewater is left to the environment. For example, U.S. Pat. No. 5,980,739 to Jowett et al teaches a wastewater treatment system including an aerobic filter medium, particularly polyurethane foam particles and the like, as a biofilter. Also, U.S. Pat. No. 5,762,784 also to Jowett et al teaches a water treatment apparatus which includes a container having apertures through the walls thereof and being opened to the atmosphere filled with open celled foam material for use in the treatment of wastewater.